1. Department of Gynecology, Qianjiang Central Hospital of Hubei Province, Qianjiang, 433100, Hubei, China
2. Department of Obstetrics and Gynecology, Wuhan Tongji Aerospace City Hospital, Wuhan, 430416, Hubei, China
3. Department of Obstetrics and Neurology, The Third Clinical Medical College of China Three Gorges University, Gezhouba Central Hospital, Yichang, 443002, Hubei, China